Pressure responsive device and its manufacture



p 1931.- E. o. STOUT ET AL 1,821,950

PRESSURE RESPONSIVE DEVICE AND ITS MANUFACTURE Filed lay :51, 1927 2Sheets-Sheet 1 III umlul III III

III

II I II III ' Sept. 8, 1931.

E. O. STOUT ET AL PRESSURE RESPONSIVE DEVICE AND ITS MANUFACTURE Filedlay 31, 1927 2 Sheets-Sheet 2 m lllllllllllllll gh U L Q m JHWMMLPatented Sept- 8, 1931 UNITED STATES PATENT OFFICE ma 0. STOOT ANDOT'I'O I. SUMMERS, F DAYTON, OHIO, ASSIGNORS, BY KESNE AS- SIGNKENTS,.l'O IBI GIDAIBE CORPORATION, A CORPORATION OF DELAWARE PREBUBERESPONSIVE DEVICE AN D ITS MANUFACTURE Application filed m :1, 1921.Serial no. 195,232.

This invention relates to the manufacture of automatic controllersincluding a pressure responsive element, and particularly to pressureresponsive controllers for refrigerating ne object of the lnvention isto simplify the construction and reduce the cost of manufacture of apressure responsive element of the type having one or more flexiblewalls between which apressure fluid may be confined.

' A further object is to increase the durability of pressure responsiveelementsof this type.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of one form of the presentinvention is clearly shown.

In the drawings:

Fig. 1 is a plan view showing the sheet metal parts from which aflexible wall or diaphragm of the pressure responsive element 1smanufactured 25 Fig. 2 is a sectional view of one of the d aphragmswhich has been formed from a d1sc punched from the opening shown in F1g. 1 which is drawn to a smaller scale than Fig. 2;

Fig. 3 is a sectional view showing the attachment of the diaphragm to asolid body by a screw to which the diaphragm is soldered;

, Fig. 4 is a sectional view ShOWlIlg the attachment of the diaphragmand screw to a cap preparatory to washing the diaphragm;

Fig. 5 is anenlarged sectional view of a pressure responsive elementformed-by two telescopically engaged diaphragms of the type shown inFlg. 4, these diaphragms being secured together by solder which isconfined by enclosing ring;

Fig. 6 is a fragmentar sectional v1ew of controlling apparatus inc udingthe pressure res on'sive element shown in F g. 5;

ig. 7 is a fragmentary sectional v1ew on an enlarged scale showing themethod of attaching the upper flexible diaphragm of the pressureresponsive element to a moving part of the controller; and

Fig. 8 is an edge v1ew of a diaphragm 60 which has been punched from asingle sheet of diaphragm material. This view shows the tendency of thediaphragm to be distorted, due to the formation of its flan e.

Referring to Figs. 1 and 2,.eac'h diaphragm or half shell, such as shell20, is formed by punching. superposed discs from pieces 21 and 22 ofsheet diaphragm material such as phosphor bronze, the grain of the sheet21 being at least transverse to and preferably at right angles to thegrain of the piece 22, as indicated by the broken lines in Fig. 1. Thesesuperposed discs are simultaneously formed into nested cups 23 and 24,.

thereby providing a flat laminated end wall 25 and a laminated annularflange 26. The wall 25 is provided with a central 0 ening 27. In similarfashion, another hal shell or diaphragm is formed, thereby comprisingnested cups 31 and 32 providin a laminated end wall 33 and a laminateannular flange 34. If either of the diaphra ms 20 or 30 were formed bypunching and s aping a single thickness of diaphragm material, theoperation of formin the annular flanges would result in producing asomewhat distorted diaphragm 35, as shown in Fig. 8. By punching andforming the diaphragm from superposed plates or sheets of material withthe grain of one sheet transverse to the grain of the other sheet, thetendency of one of the diaphragm cups to be distorted is counteracted bythe tendency of the other to become distorted in a different direction.

After the diaphragms have been formed in the manner described, eachdiaphragm is attached by screws to a flat solid block 36. For example,the diaphragm 20 is attached to the block 36 by a solid screw 37; andthe diaphragm 30 is attached by a hollow screw 38, shown in Fig. 5, inorder to admit pressure fluid to the space between the diaphragms afterthey are assembled. The

clamping of a diaphragm to a solid block' holds the diaphragm end wallsubstantially fiat during the process of soldering the head of thescrew, such as screw 37, to the diaphragm, the soldering being indicatedby numeral 39 in Fig. 3.

After soldering the central screw to the diaphragm, the assembly isremoved from the block and a cap 40 is attached to each of the screws 37or 38, as shown in Fig. 4, there being a sealin gasket 41, preferably ofvellumoid, locate between the bottom of the cap 40 and the diaphragm.-This gasket prevents liquid from entering between the iaphragmlaminations durin the subseuent operation of washing t e assembly.$Vashin is effected prefera 1y by a ten er cent so ution' of soda. Afterboth iaphragms 20 and 30 have been washed, they are assembled with a diahragm rin as shown in Fig. 5; and sol er, indicate by numeral 43, islaced in the annular groove which is provi ed between the flange 34 ofthe diaphragm 30 and the ring 42. After this assembling 0 eration andbefore removing the caps 40, t e assembly may be washed again inasodasolution and is then dried thoroughl Following this, the caps 40are remove and the assembly is heated to about 240 F. for a period of 30minutes in order to thorou hly dry the interior of the assembly. Thenthe assembly is submerged in a suitable oil, which tends to collect anysmall particles of solder which are loose therein. The oil is drainedfrom the assembly to remove these and other foreign particles.

This assembly, which is called the pressure responsive element 44, maybe assoclated with any suitable type of pressure responsivecontroller,for example, the controller 50 shown in section'in Fig. 6.The controller 50 includes a base 51 supporting a tube 52, which issecured to the base 51 by a. clamping nut 53 cooperating with thethreaded extension 54 of the tube 52. Adjacent its up er end, the tube52 supports a flat plate 55. he hollow screw 38, which has beenpreviously soldered to the diaphragm 30, is screwed into a threaded bore56 in the tube 52 in order to attach the element 50 to the tube 52 andto clamp between the diaphragm 30 and the plate the vellumoid disc 41,which operates to seal this joint. The screw 37 of the up er diaphragm20 cooperates with the threa ed opening 57 in a link member 58 whichtransmits motion from the element 50 to a lever 59 which is pivoted at60 upon an ear 61 extending vertlcall above a diaphragm cage 62. Theleft han end of the lever 59 is not shown, but it will be understoodthat the lever is connected to a suitable controller such as an electricswitch for controlling the driving motor of a refrigerating machine. Thescrew 37 and nut member 58 cooperate to attach the element 50 to the art58 and to clam a vellumoid gasket 64 tween the upper iaphragm 20 and adisc 63 attached to the nut 58. The cage 62 is provided with an opening65 for receiving the link or nut element 58, and the opening 65 issurrounded by a flange 66, which is arranged to be engaged by a spacer69 attached to the nut 58, and, in that manner, to provide a stop forting annular flanges, and means limiting the u ward movement of thediaphragm 20. he tube 52,which communicates with the interior of thepressure responsive element, is connected by a pipe 70 with a vessel(not shown) containing a volatile liquid and generally known as athermostat bulb adapted to be located within the cooling chamber or nearthe evaporator of a mechanical refrigerator.

The discs 63 and 55 cooperate with the upper and lower diaphragms,respectively, to imit the approaching movement of the diaphragmsrelative toeach other.

Aside from facilitating the manufacture of a diaphragm wall, which isfree from distortion, the laminated construction is more durable andthere is less danger of escape of the pressure fluid. The diaphragms arerequired to withstand certain pressures without distorting and if thesediaphra ms are formed from a relatively thick s eet of metal, they areapt to crack along the grain of said metal at the point where they arebent to form the cup. In the present invention this cracking at thegrain is obviated. By utilizing thin sheet metal which will bend morereadily, cups can be formed therewith without crackin the same, and, ofcourse it is then desira le to use more than one lamina to providesuflicient strength to the diaphragm. Thus it is apparent that by virtueof the present invention a strong, durable and gas-tight diaphr'a hasbeen provided while the desired exibility is still maintained.

While the form of embodiment of the present invention as hereindisclosed, constitutes apreferred form it is to be understood that otherforms might be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

1. A pressure responsive element comprising two diaphragms located inparallel, spaced relation and having telescqpically fitor joinin theflanges, said means comprising a meta ring fitting around the outerannular flange and curved around one edge thereof and having a ortioncooperating with the inner annular ange to define an annular groove, anda bonding material located in the groove.

2. The method of making a pressure res onsive element which consists inassemb 'ng two diaphragms, one of which is rovided with an aperture toadmit fluid mto the space between the diaphragms, in joining them attheir edges by a metallic bond, in

substantially filling the space within the element with an oily liquidto collect particles of metal or foreign matter, and in drawing theliquid from the element in order to remove said particles with theliquid.

3. The method of making a pressure responsive element which consists inassembling two diaphragms, one of which is proa 3.1-. mar-23.2w

vided with an aperture to admit fluid into the space between thediaphragms, in joining them at their edges by a metallic bond, inintroducing a cleansing liquid within the element and withdrawing saidliquid, in drying the element, in substantially filling the space withinthe element with an oily liquid to collect particles of metal or foreignmatter, and in drawing the liquid from the element in order to removesaid particles with the liquid.

4. The method of making a diaphragm which comprises simultaneouslycupping a plurality of grained sheet metal plates with the grain of theplates at right angles to the grain of an adjacent plate.

5. The method of making a laminated diaphragm for a pressure responsiveelement which comprises superposing a plurality of sheet metal plateswith the grain of one plate transverse to the grain of another plate,punching out discs of the desired size from said superposed plates, andsimultaneously cupping the superposed discs into a flanged laminatedbody substantially as described.

In testimony; whereof we hereto aflix our signatures.

ELMER O. STOUT. OTTO M. SUMMERS.

